It is known in the art to use various hand-operated and power-driven machines that are used by butchers and meatpacking houses to mechanically tenderize various types of meat, fish and poultry. These machines comprise a plurality of blade segments that are aligned at selected distances for penetration into the meat. These blades cut the tendons or connective tissues in the meat with very fine incisions and thereby tenderize the meat. The blade segments are movably connected to a handle means which, when pulled down, will lower the blades into the meat section positioned below the blades. The blade assembly is connected to spring means, which easily allow the downward and return upward movement of the blade assembly after the tenderizing step. Some of these type machines are those disclosed in U.S. Pat. Nos. 3,283,360; 3,583,025; 5,085,614; 5,342,235 and 5,525,102.
In U.S. Pat. No. 3,283,360 (Tamain), a tenderizer is disclosed utilizing an assembly of close metal blades that are driven by an electric motor. The reciprocating movement of the blades driven by the motor forces them into the meat and withdraws them automatically. When the blade grid or assembly of blades is in position they are surrounded by a frame 35 which in turn is supported by two rods 36. All four sides of blades or cutting assembly 22 are surrounded by the frame 35. Thus, the frame 35 of Tamain must be kept level to prevent wear and/or breakage of the tenderizer when in constant use.
In Jaccard, U.S. Pat. No. 3,583,025, (hereinafter "Jaccard I"), a similar blade assembly 42 made up of blades 44 is used. This assembly also is completely surrounded by a frame or stripper plate 46 which, as in Tamain, requires means to hold the blade assembly level to prevent kiltering of the assembly and eventual wear or breakage. While the Jaccard tenderizer has been very successful, one serious drawback has been to keep the blade assembly level when in use. The adjustable screw nuts that hold the vertical columns in place can easily loosen and cause the columns to move thereby allowing the blade assembly to hit the meat unevenly. Each of the stripper plates or assemblies 46 of Jaccard are connected to two columns that are held in parallel alignment by screw nuts located at the upper section of the blade assembly frame.
In Bourret, U.S. Pat. No. 5,085,614, the same or similar stripper plate 46 as used by Jaccard and Tamain is shown. In front view FIG. 1 and side view FIG. 2, Bourret shows that his stripper plate completely surrounds the array of blades or blade assembly 12. In FIG. 2 of Bourret, his separator is shown (unnumbered) having an extending handle just over his element 17. The unnumbered separator is attached on grid 17 at both the front and the back. Means must also be used in Bourret to keep the stripper plate even to prevent wear.
In Watanabe, U.S. Pat. No. 5,342,235, an automatic meat tenderizer is shown but is quite dissimilar to the Jaccard or Bourret devices. Watanabe, however, also completely encloses his blades or needles by connecting members 29.
In Jaccard, U.S. Pat. No. 5,525,102 ("Jaccard II"), a blade assembly unit for use with a mechanical meat tenderizer is disclosed which has a novel stripper frame assembly 15. The type of mechanical meat tenderizer in Jaccard II is the same type of tenderizer used in the present invention except the present invention provides for a greatly improved performance and longevity of the stripper frame. By providing a novel locking mechanism, the present invention ensures an even contact of the stripper frame with the meat.
In all of the above-discussed prior art, the mechanisms that hold the stripper frames in place and prevent lateral movement are not as secure as they need to be. Often, the prior art adjustable screw nuts that hold the peripheral sections or columns of the blade assembly in place will become loose thereby causing severe wear problems. When the adjustable screw nuts are allowed to turn it causes one side of the stripper frame assembly to be either higher or lower than the other side (as shown in FIG. 2). This will make the stripper frame assembly cock and jam up the tenderizing machine. When the screw nuts turn or loosen, it will eventually break the stripper frame assembly.